If I understand you correctly, this would depend on what program you want to use to read the email on each device. If you're just using a web browser, then mail isn't locally cached on your PC or tablet, and so it wouldn't matter. Just use a web browser on each.
If you wanted to use a local client email program (that downloads mail to your PC), you would need to use IMAP as your mail protocol so that everything was always synchronized, regardless of which device you were using.
Microsoft Support article: POP, IMAP, and SMTP Settings for Outlook.com
https://support.microsoft.com/en-gb/office/pop-imap-and-smtp-settings-for-outlook-com-d088b986-291d-42b8-9564-9c414e2aa040
Edited by Shplad, 03 April 2024 - 10:45 AM.